FURTHER IMPROVEMENTS IN THE YIELD OF MONOGLYCERIDES DURING ENZYMATIC GLYCEROLYSIS OF FATS AND OILS

Three approaches were used in an effort to increase the yield of monoglycerides (MG) during the lipase catalyzed reaction of glycerol with triglyceride fats and oils: i) various commercially available lipases were screened for ability to catalyze MG synthesis; ii) mixtures of lipases were compared with single lipases; and iii) two-step temperature programming was applied during the reaction. Of these, temperature programming was found to be the most effective. With an initial temperature of 42-degrees-C for 8-16 hr followed by incubation at 5-degrees-C for up to 4 days, a yield of approximately 90 wt% MG was obtained from beef tallow, palm oil and palm stearin. When the second incubation temperature was greater than 5-degrees-C, the yield of MG was progressively lower with increasing temperature. In the case of screening of newly available commercial lipase preparations, lipases from Pseudomonas sp. were found to be most effective, giving a yield of approximately 70 wt% MG at 42-degrees-C from tallow. Lipases from Geotrichum candidum, Penicillium camembertii (lipase G) and Candida rugosa were inactive. A mixture of lipases from Penicillium camembertii and Humicola lanuginosa was found to be more effective than either enzyme alone, giving a yield of approximately 70 wt% MG using beef tallow or palm oil. A mixture of Penicillium camembertii lipase with either Pseudomonas fluorescens lipase or Mucor miehei lipase was not more effective than Pseudomonas fluorescens or Mucor miehei lipase alone.